This disclosure relates to seat suspension.
Active suspension systems for motor vehicle seats move the seat up and down relative to the floor in order to reduce road-induced vibration in the seat. As the seat is raised from its nominal center height, the distance from the seat to floor-mounted control pedals changes. This can cause uncomfortable pressure on the back of the user's thighs, and when the excursion is large enough, eventual loss of contact of the driver's feet with the pedals.
U.S. Pat. No. 4,494,794 relates to an active vehicle seat suspension system which aims to prevent loss of contact between the feet of the seat occupant and control pedals of the vehicle. The system includes linkages that connect the seat to the base and which are used to control forward/backward and tilting motions of the seat bottom as the seat moves up and down relative to the floor. The system causes the occupant's ankles to remain stationary whereas his knees swing about an axis through his ankles.